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51.
52.
Teruyoshi Nagamitsu Tanaka Kenta Naoki Inari Haruka Horita Koichi Goka Tsutom Hiura 《Journal of Insect Conservation》2007,11(2):123-130
To assess the impact of Bombus terrestris invasion on the foraging efficiency of native Japanese bumblebees, consumption and acquisition of floral resources during
foraging on flowers of native Japanese plant species were investigated using enclosures with three treatments: one with only
B. terrestris (exotic), one with both B. terrestris and native Japanese bumblebee species (mixed), and one with only Japanese species (native), but with the bumblebee density
held constant. Changes in the body mass of queens and the nest mass of colonies for two days did not significantly differ
among four combinations of the species and treatment, B. terrestris in the exotic and mixed treatments and Japanese species in the mixed and native treatments. Thus, it is not clear that B. terrestris has higher foraging efficiency than native species and that B. terrestris individuals more negatively affect the foraging efficiency of native species than individuals of the native species themselves.
The nectar standing crop of Cirsium kamtschaticum was smaller in the exotic treatment than in the mixed and native treatments. However, this may have been an artifact of differences
in the numbers of flowers in the various treatments.
T. Nagamitsu and T. Kenta contributed equally to this work 相似文献
53.
Masuya H Sezutsu H Sakuraba Y Sagai T Hosoya M Kaneda H Miura I Kobayashi K Sumiyama K Shimizu A Nagano J Yokoyama H Kaneko S Sakurai N Okagaki Y Noda T Wakana S Gondo Y Shiroishi T 《Genomics》2007,89(2):207-214
Mammal-fish-conserved-sequence 1 (MFCS1) is a highly conserved sequence that acts as a limb-specific cis-acting regulator of Sonic hedgehog (Shh) expression, residing 1 Mb away from the Shh coding sequence in mouse. Using gene-driven screening of an ENU-mutagenized mouse archive, we obtained mice with three new point mutations in MFCS1: M101116, M101117, and M101192. Phenotype analysis revealed that M101116 mice exhibit preaxial polydactyly and ectopic Shh expression at the anterior margin of the limb buds like a previously identified mutant, M100081. In contrast, M101117 and M101192 show no marked abnormalities in limb morphology. Furthermore, transgenic analysis revealed that the M101116 and M100081 sequences drive ectopic reporter gene expression at the anterior margin of the limb bud, in addition to the normal posterior expression. Such ectopic expression was not observed in the embryos carrying a reporter transgene driven by M101117. These results suggest that M101116 and M100081 affect the negative regulatory activity of MFCS1, which suppresses anterior Shh expression in developing limb buds. Thus, this study shows that gene-driven screening for ENU-induced mutations is an effective approach for exploring the function of conserved, noncoding sequences and potential cis-regulatory elements. 相似文献
54.
Ujifuku Kenta Fujimoto Takashi Sato Kei Morofuji Yoichi Muto Hideki Masumoto Hiroshi Nakagawa Shinsuke Niwa Masami Matsuo Takayuki 《Cellular and molecular neurobiology》2022,42(4):997-1004
Cellular and Molecular Neurobiology - Metastatic brain tumors have poor prognoses and pose unmet clinical problems for the patients. The blood–brain barrier (BBB) implication is supposed to... 相似文献
55.
Takanori Yanagi Kenta Ito Akiha Nishihara Reika Minamino Shoko Mori Masayuki Sumida Chikara Hashimoto 《Development, growth & differentiation》2015,57(3):218-231
The dorsal blastopore lip (known as the Spemann organizer) is important for making the body plan in amphibian gastrulation. The organizer is believed to involute inward and migrate animally to make physical contact with the prospective head neuroectoderm at the blastocoel roof of mid‐ to late‐gastrula. However, we found that this physical contact was already established at the equatorial region of very early gastrula in a wide variety of amphibian species. Here we propose a unified model of amphibian gastrulation movement. In the model, the organizer is present at the blastocoel roof of blastulae, moves vegetally to locate at the region that lies from the blastocoel floor to the dorsal lip at the onset of gastrulation. The organizer located at the blastocoel floor contributes to the anterior axial mesoderm including the prechordal plate, and the organizer at the dorsal lip ends up as the posterior axial mesoderm. During the early step of gastrulation, the anterior organizer moves to establish the physical contact with the prospective neuroectoderm through the “subduction and zippering” movements. Subduction makes a trench between the anterior organizer and the prospective neuroectoderm, and the tissues face each other via the trench. Zippering movement, with forming Brachet's cleft, gradually closes the gap to establish the contact between them. The contact is completed at the equator of early gastrulae and it continues throughout the gastrulation. After the contact is established, the dorsal axis is formed posteriorly, but not anteriorly. The model also implies the possibility of constructing a common model of gastrulation among chordate species. 相似文献
56.
Takeshi Inagaki Satoshi Iwasaki Yoshihiro Matsumura Takeshi Kawamura Toshiya Tanaka Yohei Abe Ayumu Yamasaki Yuya Tsurutani Ayano Yoshida Yoko Chikaoka Kanako Nakamura Kenta Magoori Ryo Nakaki Timothy F. Osborne Kiyoko Fukami Hiroyuki Aburatani Tatsuhiko Kodama Juro Sakai 《The Journal of biological chemistry》2015,290(7):4163-4177
Polycomb repressive complex 1 (PRC1) plays an essential role in the epigenetic repression of gene expression during development and cellular differentiation via multiple effector mechanisms, including ubiquitination of H2A and chromatin compaction. However, whether it regulates the stepwise progression of adipogenesis is unknown. Here, we show that FBXL10/KDM2B is an anti-adipogenic factor that is up-regulated during the early phase of 3T3-L1 preadipocyte differentiation and in adipose tissue in a diet-induced model of obesity. Interestingly, inhibition of adipogenesis does not require the JmjC demethylase domain of FBXL10, but it does require the F-box and leucine-rich repeat domains, which we show recruit a noncanonical polycomb repressive complex 1 (PRC1) containing RING1B, SKP1, PCGF1, and BCOR. Knockdown of either RING1B or SKP1 prevented FBXL10-mediated repression of 3T3-L1 preadipocyte differentiation indicating that PRC1 formation mediates the inhibitory effect of FBXL10 on adipogenesis. Using ChIP-seq, we show that FBXL10 recruits RING1B to key specific genomic loci surrounding the key cell cycle and the adipogenic genes Cdk1, Uhrf1, Pparg1, and Pparg2 to repress adipogenesis. These results suggest that FBXL10 represses adipogenesis by targeting a noncanonical PRC1 complex to repress key genes (e.g. Pparg) that control conversion of pluripotent cells into the adipogenic lineage. 相似文献
57.
Wada K Maeda YY Watanabe K Oshio T Ueda T Takahashi G Yokohama M Saito J Seki Y Takahama S Ishii R Shitara H Taya C Yonekawa H Kikkawa Y 《Mammalian genome》2011,22(11-12):693-702
The Rinshoken cataract (rct) mutation, which causes congenital cataracts, is a recessive mutation found in SJL/J mice. All mutants present with opacity in the lens by 2?months of age. The rct locus was mapped to a 1.6-Mb region in Chr 4 that contains the Foxe3 gene. This gene is responsible for cataracts in humans and mice, and it plays a crucial role in the development of the lens. Furthermore, mutation of Foxe3 causes various ocular defects. We sequenced the genomic region of Foxe3, including the coding exons and UTRs; however, no mutations were discovered in these regions. Because there were no differences in Foxe3 sequences between the rct/rct and wild-type mice, we inferred that a mutation was located in the regulatory regions of the Foxe3 gene. To test this possibility, we sequenced a 5' noncoding region that is highly conserved among vertebrates and is predicted to be the major enhancer of Foxe3. This analysis revealed a deletion of 22-bp located approximately 3.2-kb upstream of the start codon of Foxe3 in rct mice. Moreover, we demonstrated by RT-PCR and in situ hybridization that the rct mutant has reduced expression of Foxe3 in the lens during development. We therefore suggest that cataracts in rct mice are caused by reduced Foxe3 expression in the lens and that this decreased expression is a result of a deletion in a cis-acting regulatory element. 相似文献
58.
Kaneda K Saitoh F Shibusawa H Maegawa H Saniabadi AR Kashiwagi N Matsukawa A 《Cytokine》2011,56(2):508-514
Activated neutrophils and monocytes produce interleukin (IL)-8, a pro-inflammatory chemokine, but also IL-1 receptor antagonist (IL-1ra), which is an anti-inflammatory cytokine. We were interested to see the profiles of IL-8 and IL-1ra in the colonic tissue and in the peripheral blood leukocytes (PBL) during the development of immune complex induced colitis in rabbits. IL-1ra and IL-8 in PBL were measured in 26 rabbits at time 0 h, 24 h, and 48 h after induction of colitis. The colons were removed at 48 h for measuring myeloperoxidase (MPO), ulcer area, IL-1ra and IL-8. Epithelial damage, crypt abscess formation and leukocyte infiltration of the colonic tissue were major features of this colitis model. During the development of colitis, there was an increase in circulating neutrophils and monocytes (P < 0.0001), but not lymphocytes. Likewise, elevated amounts of IL-1ra (P = 0.0001) and IL-8 (P = 0.0219) production by PBL were observed following induction of colitis. Flow cytometry revealed major source of IL-1ra was monocytes, while the main sources of IL-8 were neutrophils and monocytes. There was correlation between MPO and ulcer area (Rs = 0.6327, P < 0.0001). At 24 h, PBL from MPOHigh group (n = 11) showed increased IL-1ra (P = 0.027) and IL-8 (P = 0.0128) levels vs MPOLow group (n = 15). IL-8 production by PBL showed correlation with tissue MPO (Rs = 0.4273, P = 0.0295). The colitis in this model was associated with an increase in circulating monocytes and neutrophils, which released increased amounts of IL-8 and IL-1ra. Further, IL-8 and IL-1ra showed correlation with the severity of colitis. These observations should significantly further understandings on the role of neutrophils and monocytes in the immunopathogenesis of ulcerative colitis. 相似文献
59.
60.
Ciliates and flagellates temporarily swim backwards on collision by generating a mechanoreceptor potential. Although this potential has been shown to be associated with cilia in Paramecium, the molecular entity of the mechanoreceptor has remained unknown. Here we show that Chlamydomonas cells express TRP11, a member of the TRP (transient receptor potential) subfamily V, in the proximal region of the flagella, and that suppression of TRP11 expression results in loss of the avoiding reaction. The results indicate that Chlamydomonas flagella exhibit mechanosensitivity, despite constant motility, by localizing the mechanoreceptor in the proximal region, where active bending is restricted. 相似文献